/*
 * Copyright (c) 2011, Marc-Andre Ferland - madrang@gmail.com
 * All rights reserved.
 * 
 * Redistribution and use in source and binary forms, with or without
 * modification, are permitted provided that the following conditions are met:
 *     * Redistributions of source code must retain the above copyright
 *       notice, this list of conditions and the following disclaimer.
 *     * Redistributions in binary form must reproduce the above copyright
 *       notice, this list of conditions and the following disclaimer in the
 *       documentation and/or other materials provided with the distribution.
 *     * Neither the name of the The Warrent Team nor the
 *       names of its contributors may be used to endorse or promote products
 *       derived from this software without specific prior written permission.
 *     * This software is free for non-commercial use. You may not use this
 *       software, in whole or in part, in support of any commercial product
 *       without the express consent of the author.
 * 
 * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS "AS IS" AND
 * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED
 * WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE
 * DISCLAIMED. IN NO EVENT SHALL THE WARRENT TEAM BE LIABLE FOR ANY
 * DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES
 * (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES;
 * LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND
 * ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
 * (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF THIS
 * SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
 */
using System;
using System.Runtime.InteropServices;

namespace OsHelper.UsbNet.LibUsb.Transfer
{
	/// <summary>
    /// Wraps an iso packet structure
    /// </summary>
	[StructLayout(LayoutKind.Sequential)]
	public class IsoPacket : UsbNet.Transfer.IsoPacket
	{
		private class LibUsbIsoPacket
		{
			public uint Length = 0;
			public uint ActualLength = 0;
			public UsbNet.Transfer.Status Status = (UsbNet.Transfer.Status)0;
		}
		
		private static readonly int LengthOffset = Marshal.OffsetOf(typeof(LibUsbIsoPacket), "Length").ToInt32();
		private static readonly int ActualLengthOffset = Marshal.OffsetOf(typeof(LibUsbIsoPacket), "ActualLength").ToInt32();
		private static readonly int StatusOffset = Marshal.OffsetOf(typeof(LibUsbIsoPacket), "Status").ToInt32();
		
		/// <summary>
		/// Creates a structure that wraps an iso packet.
		/// </summary>
		/// <param name="isoPacketPtr">The pointer to the iso packet to wrap.</param>
		public IsoPacket (IntPtr IsoPacketPtr)
		{
			this.Handle = IsoPacketPtr;
		}
		
		/// <summary>
        /// Returns the location in memory of this iso packet.
        /// </summary>
        public IntPtr Handle {
			get; private set;
		}
	
		/// <summary>
        /// Amount of data that was actually transferred. 
        /// </summary>
        public int ActualLength
        {
            get { return Marshal.ReadInt32(this.Handle, ActualLengthOffset); }
            set { Marshal.WriteInt32(this.Handle, ActualLengthOffset, value); }
        }
        /// <summary>
        /// Length of data to request in this packet. 
        /// </summary>
        public int Length
        {
            get { return Marshal.ReadInt32(this.Handle, LengthOffset); }
            set { Marshal.WriteInt32(this.Handle, LengthOffset, value); }
        }
        /// <summary>
        /// Status code for this packet. 
        /// </summary>
		public UsbNet.Transfer.Status Status
        {
            get { return (UsbNet.Transfer.Status)Marshal.ReadInt32(this.Handle, StatusOffset); }
            set { Marshal.WriteInt32(this.Handle, StatusOffset, (int)value); }
        }
		
    }
}
